From f2172d8e2af4e1a372514103467450cfc4c51d18 Mon Sep 17 00:00:00 2001
From: Matthias Koefferlein <matthias@klayout.de>
Date: Sat, 31 May 2025 17:33:44 +0200
Subject: [PATCH] Extension of the L2N/LVSDB format to support deleted
 terminals and parameters

Previously, when deleting parameters or terminals from device
definitions, these parameters or terminals re-appeared in the
netlist browser, because they were generated from the
template class (e.g. "A" and "B" from "RES").

An additional token is added that indicates whether to
remove all entries before adding new ones.

This feature is backward-compatible and LVSDB/L2N files have to
be generated from new KLayout versions to make use of that
feature.
---
 src/db/db/dbLayoutToNetlistFormatDefs.h |  9 ++++++---
 src/db/db/dbLayoutToNetlistReader.cc    | 10 ++++++++++
 src/db/db/dbLayoutToNetlistWriter.cc    | 26 +++++++++++++++++++++----
 3 files changed, 38 insertions(+), 7 deletions(-)

diff --git a/src/db/db/dbLayoutToNetlistFormatDefs.h b/src/db/db/dbLayoutToNetlistFormatDefs.h
index 6c7f4f3fe..bea7dbd60 100644
--- a/src/db/db/dbLayoutToNetlistFormatDefs.h
+++ b/src/db/db/dbLayoutToNetlistFormatDefs.h
@@ -79,7 +79,10 @@ namespace db
  *    circuit(<name> [circuit-def]) - circuit (cell) [short key: X]
  *
  *  [class]:
- *    class(<name> <template> [template-def])  - a device class definition (template: RES,CAP,...) [short key: K]
+ *    class(<name> <template> <full-specs>? [template-def])  - a device class definition (template: RES,CAP,...) [short key: K]
+ *                                    "fill_specs" is an optional value (0 or 1), indicating that all parameters and terminals
+ *                                    are listed. For "1", the reader will remove all specs from the template before rebuilding
+ *                                    them.
  *
  *  [device]:
  *    device(<name> <class> [device-abstract-terminal|any]*)
@@ -158,8 +161,8 @@ namespace db
  *    [template-param|template-terminal|any]*
  *
  *  [template-param]:
- *    param(<name> <primary>? <default-value>*)    - defines a template parameter [short key: E]
- *                                    ('primary' is a value: 0 or 1)
+ *    param(<name> <primary> <default-value>)    - defines a template parameter [short key: E]
+ *                                    ('primary' is a value: 0 or 1, 'default_value' is a float)
  *
  *  [template-terminal]:
  *    terminal(<name>)              - defines a terminal [short key: T]
diff --git a/src/db/db/dbLayoutToNetlistReader.cc b/src/db/db/dbLayoutToNetlistReader.cc
index ac18e9bf9..43b3850bd 100644
--- a/src/db/db/dbLayoutToNetlistReader.cc
+++ b/src/db/db/dbLayoutToNetlistReader.cc
@@ -391,6 +391,9 @@ void LayoutToNetlistStandardReader::read_netlist (db::Netlist *netlist, db::Layo
       read_word_or_quoted (class_name);
       read_word_or_quoted (templ_name);
 
+      int full_specs = 0;
+      try_read_int (full_specs);
+
       if (netlist->device_class_by_name (class_name) != 0) {
         throw tl::Exception (tl::to_string (tr ("Duplicate definition of device class: ")) + class_name);
       }
@@ -407,6 +410,13 @@ void LayoutToNetlistStandardReader::read_netlist (db::Netlist *netlist, db::Layo
         dc = dct->create ();
       }
 
+      //  start with tabula rasa on "full specs"
+      if (full_specs != 0) {
+        dc->clear_equivalent_terminal_ids ();
+        dc->clear_parameter_definitions ();
+        dc->clear_terminal_definitions ();
+      }
+
       dc->set_name (class_name);
       netlist->add_device_class (dc);
 
diff --git a/src/db/db/dbLayoutToNetlistWriter.cc b/src/db/db/dbLayoutToNetlistWriter.cc
index df2499492..092e998bb 100644
--- a/src/db/db/dbLayoutToNetlistWriter.cc
+++ b/src/db/db/dbLayoutToNetlistWriter.cc
@@ -294,11 +294,29 @@ void std_writer_impl<Keys>::write_device_class (TokenizedOutput &stream, const d
   TokenizedOutput out (stream, Keys::class_key);
   out << tl::to_word_or_quoted_string (cls->name ()) << tl::to_word_or_quoted_string (temp_name);
 
+  //  we need to issue all specs if some are deleted
+  bool full_specs = false;
+
+  const std::vector<DeviceParameterDefinition> &pd_temp = temp_class->parameter_definitions ();
+  for (auto p = pd_temp.begin (); p != pd_temp.end () && ! full_specs; ++p) {
+    full_specs = ! cls->has_parameter_with_name (p->name ());
+  }
+
+  const std::vector<DeviceTerminalDefinition> &td_temp = temp_class->terminal_definitions ();
+  for (auto t = td_temp.begin (); t != td_temp.end () && ! full_specs; ++t) {
+    full_specs = ! cls->has_terminal_with_name (t->name ());
+  }
+
+  //  new token: indicates that all specs will be listed
+  if (full_specs) {
+    out << tl::to_string (1);
+  }
+
   bool any_def = false;
 
   const std::vector<DeviceParameterDefinition> &pd = cls->parameter_definitions ();
-  for (std::vector<DeviceParameterDefinition>::const_iterator p = pd.begin (); p != pd.end (); ++p) {
-    if (! temp_class->has_parameter_with_name (p->name ()) || !same_parameter (*p, *temp_class->parameter_definition (temp_class->parameter_id_for_name (p->name ())))) {
+  for (auto p = pd.begin (); p != pd.end (); ++p) {
+    if (full_specs || ! temp_class->has_parameter_with_name (p->name ()) || !same_parameter (*p, *temp_class->parameter_definition (temp_class->parameter_id_for_name (p->name ())))) {
       if (! any_def) {
         out << endl;
       }
@@ -308,8 +326,8 @@ void std_writer_impl<Keys>::write_device_class (TokenizedOutput &stream, const d
   }
 
   const std::vector<DeviceTerminalDefinition> &td = cls->terminal_definitions ();
-  for (std::vector<DeviceTerminalDefinition>::const_iterator t = td.begin (); t != td.end (); ++t) {
-    if (! temp_class->has_terminal_with_name (t->name ())) {
+  for (auto t = td.begin (); t != td.end (); ++t) {
+    if (full_specs || ! temp_class->has_terminal_with_name (t->name ())) {
       if (! any_def) {
         out << endl;
       }